RedWave Energy, a local startup developing technology that harvests heat energy, closed a $5.5 million round of funding this week that will help bring it closer to a prototype.

RedWave is working to save the lower-temperature heat put off during manufacturing processes — like those at glass factories or electric power generation plants — and convert that heat into electricity and get it back on the grid, said CEO and co-founder Jim Nelson.

“A huge amount of heat is wasted in industrial processes, and the reason it’s wasted is because it’s no longer hot enough to turn a turbine, or be useful in any other application,” he said.

When he says lower-temperature heat, Nelson is talking about less than 300 C — pretty hot for normal standards (water boils at 100 C), but not when it comes to making electricity.

RedWave’s technology uses tiny antennas — millions per square inch — formed and tuned to pick up the wavelengths from the heat waste, Nelson said. The electrons then flow off the antennas and are turned into electricity that can be placed back on the grid.

“If you light a match and put your hand over it, the concept you have is heat, but what you’re really doing is absorbing the electromagnetic waves,” he said.

The Wheaton-based startup brought together scientists from around the county. Idaho National Lab developed the nanoantenna technology, and experts at the University of Colorado-Boulder developed the technology that funnels the electrons off the antenna.

It’s also working with a manufacturer in Cambridge, Mass., that can help make the nanoantenna-filled film.

RedWave plans to focus its operations on developing that film, rather than manufacturing it, Nelson said. Others in the industry, such as General Electric or Siemens, could then license and use the technology.

“(Our) secret sauce is really getting that film right,” he said. “We believe the best thing is for us to be the technology provider. The strength is the (intellectual property).”

Nelson founded RedWave with co-founder and CTO Pat Brady in 2011. It raised a $3 million Series A round of funding in February 2012, and in May received a $3.565 million grant from the Department of Energy’s Advanced Research Projects Agency-Energy.

The grant is distributed over three years. Nelson said he expects to start beta testing the product within a year.

“The funding will get them to a prototype, something people can hold in their hands and see work,” said Jason Blumberg, managing director of Energy Foundry.

Clean technologies such as RedWave's often have a rough time finding funding, since it takes them longer to get to market and can be more expensive to develop than a software solution would be.

Energy Foundry, which uses an investment model designed to reduce risks and time to market for energy startups, doesn’t mind taking the long-term technology risks if there are big opportunities, Blumberg said.

There are other technologies that turn waste heat into energy, but things get more complex when you start trying to harnessing the lower-temperature heat, Blumberg said. RedWave has brought together the right team of people to make it work, though, he believes.

“A lot of people wouldn't even tackle this,” he said. “It’s hard, but if anyone can solve it, these guys can.”